Summary 1 A]I Japanese local races of Daphnia have undoubtedly been derived
from the two species, D. pulex and D. ... are brachycephalic, the development of
the helmet in summer having been seen in a single lake north of Hokkaido.

longs to one of the races of D. longispina or rarely to either D. f.iicntlata or D. pulex. ... that all Japanese races of D. longispina are brachycephalic. the
development of the helmet in summer having Ix-e.n seen in a single lake north of
Hokkaido.

This illustration of a related species,
Brachycephalus ephippium shows the
reduced digits on the hands and feet.
The family
Brachycephalidae holds 47 species in two genera, Brachycephalus and Ischnocnema.